Assembly for inspecting the interior of pipes or conduits



June 17, 1969 KR MP ET 'AL J 3,450,481

ASSEMBLY FOR INSPECTING THE INTERIOR OF PIPES OR CONDUITS Filed Oct. 21, 1965 Sheet I of 4 INVENTOR6 JOSEPH J. KRAMP THEODORE A. BUTTS BY aux 7 ATTORNEYS June 17, 1969 J KRAMP ET AL 3,450,481

ASSEMBLY FOR INSPECTING THE INTERIOR 0F PIPES OR CONDUITS Filed Oct. 21, 1965 Sheet & of 4 I I I I l I llllllllllllI I IIIIIIIIIIIIII INVENTORS I as 94 2s JOSEPH J.KRAMP 12% 26 37 9 THEODORE A. BUTTS IBY, flamwz a wiy FIG. IO.

ATTORNEYS v June 17, 1969 J. J. KRAMP ET AL 3,450,481.

ASSEMBLY FOR INSPECTING THE INTERIOR OF PIPES OR CONDUITS Sheet Filed Oct. 21, 1965 j E li INVENTORS JOSEPH J. KRAMP FIG. I4.

THEODORE A. BUTTS BY Md M ATTORNEYS QFRESNEL June 17, 1969 Y J, J, KRAMP ET AL 3,450,481

ASSEMBLY FOR INSPECTING THE INTERIOR OF PIPES OR CONDUITS Filed Oct. 21, 1965 Sheet 4 of 4 FIG. l5.

REMOTE OBJECTIVE PIPE WALL MIRROR SURFACE PIPE WALL OBSERVED AREA ILLUMINATED AREA IL PRISM LAMP PIPE wAL| INVENTORS FIG. '6. JOSEPH J. KRAMP THEODOR E A. BUTTS BY L ATTORNEY) United States Patent 3,450,481 ASSEMBLY FOR INSPECTING THE INTERIOR OF PIPES 0R CONDUITS Joseph J. Kramp, 5604 Wildwood Lane, Baltimore, Md. 21209, and Theodore A. Butts, 522 Towson Ave., Lutherville, Md. 21093 Filed Oct. 21, 1965, Ser. No. 499,450 Int. Cl. G01n 21/16 US. Cl. 356-241 Claims ABSTRACT OF THE DISCLOSURE An assembly for inspecting the interior of pipes or conduits including a mobile support movable axially through the pipe, the support having a concave reflecting member mounted thereon, an illuminating member mounted proximate the reflecting member for directing light rays to the pipe periphery, the focal length of which concave reflecting member is such that the light rays from the illuminated portion of the pipe pass through the focal point of the reflecting member and are reflected by the latter in planes parallel to the longitudinal axis of the pipe, and a viewing unit at one terminal of the pipe for receiving the light rays transmitted by the reflecting memher.

This invention relates to an assembly for inspecting the interior of pipes or conduits, an object of which is the remote visual inspection of the interior of inaccessible pipes or conduits of relatively small diameter from an access point at the termination of the pipe or conduit, in order to detect defects.

Another object is to provide an assembly of the character described including an inspection unit movable through a pipe, and a viewing unit at one terminal thereof, the inspection unit transmitting an image of the inner periphery of the pipe to the viewing unit.

A further object is to provide an inspection unit including a mobile support on which a concave mirror is mounted, the unit further including a light source for illuminating the inner peripheral wall of the pipe, light rays from the illuminated wall being reflected by the mirror to a telescope forming part of the viewing unit.

Other objects are to provide an inspection unit of the character described wherein the light source is positioned centrally of the mirror and a prism surrounds the light for directing light rays outwardly through 360 towards a predetermined section of the pipe periphery; to provide an inspection unit wherein the light source is located at a point along the outer periphery of the mirror, the light source being shielded to direct light rays towards a small portion of the pipes peripheral wall, the mirror and attached light source being rotated through 360 to progressively illuminate the entire periphery of a selected pipe portion; to provide an inspection unit supported by wheel members angularly disposed with respect to each other for facilitating movement of the unit through the pipe; t provide means for remotely moving the mobile inspection unit through the pipe, and to provide a viewing unit including a carrying case, a portion of which case is adaptable for supporting a telescope forming part of the viewing unit.

Other objects of the invention will be manifest from the following description of the present preferred forms of the invention, taken in connection with the accompanying drawings, wherein:

FIG. 1 is a plan view illustrating the application of the assembly of the present invention in inspecting a sewer pipe;

FIG. 2 is a plan view of the viewing telescope forming a part of the present assembly;

3,450,481 Patented June 17, 1969 FIG. 3 is a sectional view taken along the lines 3-3 of FIG. 2, looking in the direction of the arrows;

FIG. 4 is a sectional view taken along the lines 4-4 of FIG. 1, showing to advantage the position of the inspection unit within the sewer pipe;

FIG. 5 is a longitudinal sectional view taken along the lines 55 of FIG. 4, looking in the direction of the arrows;

FIG. 6 is a sectional view taken along the lines 6-6 of FIG. 5, looking in the direction of the arrows;

FIG. 7 is a sectional view taken along the lines 7-7 of FIG. 5, looking in the direction of the arrows;

FIG. 8 is a perspective view of a caster member for the inspection unit;

FIG. 9 is a sectional view taken along the lines 99 of FIG. 5, looking in the direction of the arrows;

FIG. 10 is a fragmentary vertical sectional view of a modified form of the present invention;

FIG. 11 is a front elevational view of the form of invention shown in FIG. 10;

FIG. 12 is a sectional view taken along the lines 12-12 of FIG. 10, looking in the direction of the arrows;

FIG. 13 is an elevational view of the viewing unit illusstrating the manner in which the telescope is positioned for use in a portion of a carrying case;

FIG. 14 is a top plan view of the viewing unit;

FIG. 15 is a schematic view illustrating the manner in which light rays of a pipe wall are reflected by a mirror surface of the inspection unit and transmitted to the viewing unit; and

FIG. 16 is a schematic view illustrating the manner in which a predetermined area of the pipe periphery is illuminated by a light source for inspection.

The assembly of the present invention is adapted for inspecting the inner peripheral wall of pipes or conduits which are of a size too small to permit direct inspection b a person moving through the pipe. In FIG. 1, the assembly of the present invention is illustrated as applied to a sewer pipe 20 of conventional diameter size, e.g. 8 inches, the pipe passing through a manhole 21 at the locus of which manhole an upper portion of the pipe is cut away, as indicated at 22. The assembly of the present invention includes an inspection unit 23 which is movable through pipe 20 and a viewing unit 24 which is positioned in manhole 21 at the locus of the cut away portion 22 of the pipe.

Inspection unit 23 is shown to advantage in FIGS. 4 to 9 and includes a mobile drogue sled embodying spaced longitudinal members 25 of generally rectangular cross section, connected at intervals by transverse members 26. Intermediate members 26 is a support 27 on which a battery pack 28 or other source of electrical power is mounted. A clamp plate 29 is held in retaining engagement with battery pack 28 by retention bolts 30 and nuts 31, the former extending upwardly from support 27 through clamp plate 29.

In accordance with the present invention, opposed portions of longitudinal members 25 near the front end of the unit are notched out at 32 for the reception of suitable caster members 33. A caster member 33 is shown to advantage in FIGS. 8 and 9 and includes a top wall 34, opposed side walls 35 and end walls 36. Side walls 35 are provided with opposed elongated slots 37 disposed in a horizontal plane and adapted for the reception of an axle pin 38 which rotatably supports a caster wheel 39. Slots 37 permit relative movement of wheel 39 with respect to the remainder of the caster member for facilitating reversal in direction of the unit under operating conditions. A threaded shank 40 extends upwardly from top wall 34 and passes through longitudinal member 25 and is retained in position by a nut 41 which is threadedly engaged with the shank. End walls 36 of each caster member are provided with limit recesses 42, one of which is adapted to receive a stop pin 43 depending downwardly into the recess from longitudinal member 25. This permits limited orientation of the unit when passing through a pipe to prevent the inspection unit from riding up on the sides of the pipe wall. The unit is additionally provided with fixed rear wheels 44 which are rotatabl mounted in opposed relationship to longitudinal members 25 by suitable means 45.

It will be noted that longitudinal members 25, caster members 33 including wheels 39 and rear wheels 44 are disposed outwardly at an angle and are approximately coincident with radial lines of pipe 20, to permit optimum engagement with the arcuate portion of the pipe periphery which the wheels engage. This further facilitates centering of the unit and permits ready movement thereof through the pipe.

In accordance with the objectives of the present invention, a bearing block 46 is secured by suitable means 47 to transverse member 26 at the forward end of the unit. Block 46 is provided with an aperture adapted to receive a shaft 48 which extends through the central rear face of a concave mirror 49. A lamp receptacle 50 is fixed engaged with shaft 48, the receptacle being adapted to receive a lamp 51. A Fresnel prism 52 is placed over the lamp, and secured to receptacle 50, a front baflie 53 being cemented or secured in any other suitable fashion to the prism, to direct a cone of light rays outwardly in the manner illustrated in FIG. 16 It will be noted that lamp 51 and prism 52 are in close proximity to the concave surface of mirror 49 preferably within the confines ofthe mirrors curvature, to effect optimum results. A setscrew 54 extends through bearing block 46 for engaging and holding shaft 48 in place and to facilitate removal and replacement of parts. Power for lamp 51 i supplied by battery pack 28 through electrical circuitry 55 to lamp receptacle 50, and is controlled by an operating switch 56.

In order to move the inspection unit through a pipe, there is provided a coupler 57 secured to the aft transverse member 26 by suitable means 58. A rod 59 is engaged with coupler 57. Rod 59 is preferably of predetermined length, such as three feet and is adapted for connection with like rods as needed to move the inspection unit through the entire length of the pipe.

Viewing unit 24 comprises a conventional refracting type elbow telescope 60' having a viewing piece 61 at one end and an image-receiving member 62 at the other end. A shown to advantage in FIGS. 2 and 3, the lower portion of telescope 60 is mounted in a circular holder 63 having an upstanding peripheral wall 64 which terminates in an outwardl directed flange 65. The underface of holder 63 is provided with spaced depending lugs 66 through which bolts 67 extend into engagement with a continuous slot 68 formed in a collar 69 which is secured to the lower extremity of telescope 60. The outer periphcry of telescope 60 and collar 69 is spaced from the complemental opening of holder 63 thereby permitting adjustment of the telescope as indicated in phantom lines in FIG. 2.

For fixing telescope 60 in the selected position from the range of position indicated in FIG. 2, there is provided a locking rod 70 which extends through a sleeve attached to the upper face of holder 63. An operating handle 72 hingedly connected to the upper terminal of locking rod 70 effects vertical movement of rod 70. Rod 70 extends to a point below collar 69 where it is threaded for engagement with a nut 73. Nut 73 contacts the undersurface of collar 69 so that upon upward movement of rod 70, pressure is exerted to close slot 69 slightly. This prevents movement of adjacent bolt 67 in the slot and locks the telescope in position. Adjustment of telescope 60 is readily effected by rotation of attached holder 63.

In order to facilitate use of the telescope, the viewing unit further includes a carrying case 74, one end 75 of which is hingedly connected at 76 to the body of the case. Arcuate slotted brackets 77 are secured at one terminal on opposed edges 'of end as indicated at 78, the slotted portions of the brackets being adapted for engagement with the terminals of a transverse rod 79 at the top of the case, in opposed relation to hinge 76. The brackets limit the degree of opening of end 75 and permit the same to be open to a position uniplanar with the bottom of the case to form a firm supporting surface for the telescope. A portion of end 75 is cut out to permit telescope 60 to be placed therein, the size of the opening being such that flange 65 of holder 63 engages the point adjacent the opening to support the telescope in operative position. Case 74 is provided with conventional lock means 80, adapted to be engaged by complemental latch means 81 carried by end 75,

In operation, viewing unit is set up in manhole 21 in the manner above described and inspection unit 23 is placed in pipe 20 at an adjacent manhole or other access point, following which lamp 51 is illuminated by operation of switch 56. By virtue of the action of the Fresnel prism 52 on the light rays emanating from lamp 51, these rays are directed in cone shape to a predetermined area of the pipe as illustrated in FIG. 16. The light rays are, in turn, reflected from the pipe wall through the focal point of mirror 49 as illustrated in FIG. 15. In accordance with basic optical principals, these light rays are then reflected by the mirror surface and directed longitudinally of the pipe in parallel horizontal planes towards the viewing unit whereby the pipe periphery may be inspected for cracks, breaks, faulty joints, etc. Inspection unit 23 may be moved at any desired speed by pushing rods 59. It should be noted that by keeping track of the number and length of the rods attached to the inspection unit, ready determination may be made of the exact point above ground where a defect in the pipe occurs so that digging at the exact location of the defect may be effected. It should be further noted that best results are obtained when the focal length of the concave mirror is approximately equal to half the diameter of the pipe. Additionally, by providing a system of the present type, wherein the light rays are reflected by the concave mirror in parallel horizontal planes, the viewing unit is capable of picking up a clear image of the pipe periphery from points remote as well as near the viewing unit.

In FIGS. 10, 11 and 12, there is illustrated a modified form of the inspection unit of the present invention, designated 23 employing the same basic structure as in the form of invention illustrated in FIGS. 1 to 9. The same supporting structure is employed in that form of the invention and like parts are identified by like, primed numbers. In this form of the invention however, there are provided a pair of spaced bearing blocks 82 supported by transverse members 26', each of which bearing blocks is provided with aligned bushings 83. A shaft 84 extends through bushings 83 of bearing blocks 82 to a point forward of the unit where it is received in a complemental opening of a coupling member 85 of generally cubical shape, displacement of the shaft being prevented by means of a setscrew 86.

As shown to advantage in FIG. 12, cubical member 85 is positioned between spaced parallel support angle bars 87, which members are fixed to the rear face of a concave mirror 88 by securing means 89. A connecting rod 90 extends through openings in members 87 and through a bore in member 85 in order to effect fixed engagement of shaft 84 with concave mirror 88. It will be noted from FIG. 10 that the connection between shaft 84 and concave mirror 88 is such that the mirror is canted downwardly for reasons which will be hereinafter more fully set out. A lamp receptacle 91 is attached to the outer periphery of concave mirror 88 and is adapted for the reception of a lamp 92 which is preferably actuated through conventional slip rings by a batte1y pack in the same manner as the form of invention set out in FIGS. 1

to 9. In addition, a circular shield 93 is placed around and extends forwardly of lamp 92, the shield being of a shape to direct light rays from lamp 92 downwardly towards the pipe periphery rather than outwardly towards the viewing unit.

In accordance with the present invention, a transverse motor support 94 is mounted between longitudinal members 25' on which support an electrical motor 95 is mounted, the drive shaft of which is connected to suitable gearing indicated at 96 to a bevel gear 97. Bevel gear 97 is adapted for meshing engagement with a mating bevel gear 98 which is fixed to shaft 84 in order to effect rotation of the latter upon actuation of the motor with consequent rotation of mirror 88. The operation of the modified form of the invention is the same as described above in connection with FIGS. 1 to 9, with the exception that as the mirror is rotated, lamp 92 and shield 93 are also rotated to progressively illuminate points along the inner periphery of the pipe. By virtue of the arrangement of the mirror in this form of the invention, slight magnification of the pipe periphery will occur to facilitate the recognition of defects in the pipe. Mirror 88 may be oriented at an angle to the axis of the pipe to provide a more magnified view of a portion of the pipe periphery.

With the apparatus of the present invention, an economical means is provided for locating pipe defects, or the like, the apparatus being readily set up for operation in a minimum of time by unskilled personnel. Additionally, the assembly is inherently reliable and is rapid in operation.

While the present invention is shown and described as applied to inspection of sewer pipe, it is to be understood that it is equally applicable for the inspection of various pipes and conduits. Various other changes may be made within the scope of the claims hereto appended.

We claim:

1. An assembly for inspecting the interior of a pipe, including:

(a) a mobile support comprising spaced, parallel longitudinal members,

(b) transverse members connecting said longitudinal members,

(0) wheels rotatably mounted on said longitudinal members adjacent the terminals thereof,

((1) said wheels and longitudinal members being radially disposed with respect to the pipe for optimum engagement therewith,

(e) a concave reflecting member mounted on said support between said longitudinal members,

(f) an illuminating member mounted centrally of said concave reflecting member for directing light rays to the pipe periphery,

(g) the focal length of said concave reflecting member being such that the light rays from the illuminated portion of the pipe pass through the focal point of the reflecting member and are reflected by the latter in planes parallel to the longitudinal axis of the pipe,

(h) a viewing unit at one terminal of the pipe for receiving the light rays transmitted by said reflecting member, and

(i) means associated with said illuminating member to block direct light from reaching said viewing unit.

2. The assembly of claim 1, wherein said viewing unit comprises:

(a) atelescope,

(b) a support for said telescope, said support including,

(c) a case,

(d) one end of said case being hingedly connected to the body of the case,

(e) means engageable with said end for permitting the latter to drop to a point uniplanar with the bottom of said case for forming a supporting surface,

-(f) the end being provided with an opening through which the lower portion of the telescope extends,

(g) the viewing unit further including a collar secured to the lower extremity of said telescope,

(h) a circular holder secured to said collar and rotatably mounted in the opening of said case end,

(i) said telescope being adjustably movable with respect to said circular holder, and

(j) means for locking said telescope and circular holder in predetermined position.

3. An assembly for inspecting the interior of a pipe,

including (a) a mobile support comprising spaced, parallel longitudinal members,

(b) transverse members connecting said longitudinal members,

(c) wheels rotatably mounted on said longitudinal members adjacent the terminals thereof,

(d) said wheels and longitudinal members being radially disposed with respect to the pipe for optimum engagement therewith,

(e) a concave reflecting member mounted on said support between said longitudinal members,

(f) an illuminating member positioned along the periphery of the reflecting member,

(g) the focal length of said concave reflecting members being such that the light rays from the illuminated portion of the pipe pass through the focal point of the reflecting member and are reflected by the latter in planes parallel to the longitudinal axis of the pipe,

(h) a shaft fixed to, and extending outwardly from the rear face of said concave reflecting member,

(i) the connection between said shaft and concave reflecting member being such that the reflecting member is canted at an angle to the longitudinal axis of the assembly,

(j) power means connected to said shaft for rotating the latter to progressively illuminate points along the pipe periphery, and

(k) a viewing unit at one terminal of the pipe for receiving the light rays transmit-ted by said reflecting member.

4. The assembly of claim 3, wherein said viewing unit comprises:

(a) atelescope,

(b) a support for said telescope, said support including,

(c) acase,

((1) one end of said case being hingedly connected to the body of the case,

(e) means engageable with said end for permitting the latter to drop to a point uniplanar with the bottom of said case for forming a supporting surface,

(f) the end being provided with an opening through which the lower portion of the telescope extends,

'(g) the viewing unit further including a collar secured to the lower extremity of said telescope,

(h) a circular holder secured to said collar and rotatably mounted in the opening of said case end,

(i) said telescope being adjustably movable with respect to said circular holder, and

(j) means for locking said telescope and circular holder in predetermined position.

5. An assembly for inspecting the interior of a pipe,

including:

(a) a mobile support movable axially through the pipe,

(b) a concave reflecting member mounted on said support,

(c) an illuminating member mounted proximate said reflecting members and positioned between the focal point and reflecting surface of said reflecting member, for directing light rays to the pipe periphery,

(d) the focal length of said concave reflecting member being such that the light rays from the illuminated portion of the pipe pass through the focal point of the reflecting member and are reflected by the latter in planes parallel to the longitudinal axis of the pipe,

-(e) a viewing unit at one terminal of the pipe for receiving the light rays transmitted by the reflecting member, and

(f) means associated with said illuminating member to block direct light from reaching said viewing unit.

6. The assembly of claim 5, wherein:

(a) said illuminating member is mounted centrally of said concave reflecting member, and means for directing the light rays from said illuminating member in a predetermined pattern outwardly towards the inner periphery of the pipe.

7. The assembly of claim 5, wherein:

(a) said means comprises a prism.

8. The assembly of claim 5, wherein:

(a) said viewing unit comprises a telescope,

(b) a support for said telescope,

(c) means for orienting said telescope to align the latter axially with respect to the pipe, and

(d) means for adjustably rotating said support and telescope to orient the latter coincident with the longitudinal axis of the pipe.

9. An assembly for inspecting the interior of a pipe,

including:

(c) an illuminating member positioned at a point along the periphery of the reflecting member,

'(d) means for directing light rays from said illuminating member towards the pipe periphery, (e) means for canting said reflecting member at an angle to the longitudinal axis of the pipe,

=(f) the focal length of said concave reflecting member being such that 'thelight rays from the illuminated portion of the pipe pass through the focal point of the reflecting member and are reflected by the latter in planes parallel to the longitudinal axis of the pipe,

(g) means for rotating said reflecting member '-to progressively illuminate points along the pipe periphery,

(h) a viewing unit at one terminal of the pipe for receiving the light rays transmitted by the reflecting member, and

(i) means associated with said illuminating member to block direct light from reaching said viewing unit.

10. 'Ilhe assembly of claim 9, wherein (a) said viewing unit comprises a telescope,

(b) asupport for saidtelescope,

(c) means for orienting said telescope to align the latter axially with respect to the pipe, and

(d) means for adjustably rotating said support and telescope to orient the latter coincident with the longitudinal axis of the pipe.

References Cited UNITED STATES PATENTS FOREIGN PATENTS Switzerland.

RONALD L. WILBERT, Primary Examiner.

A. B. CHEW, Assistant Examiner.

U.S.,Cl. X.R. 350-6, 289 

